Surfactant-Templated Cobalt Oxide Nanoparticles: A Platform for Enhanced Pea Seeds Germination

Abstract

The pressing problem of increasing agricultural productivity and improving crop quality requires the development of new approaches to plant nutrition. One promising solution is the use of nanomaterials, in particular cobalt oxide nanoparticles (Co3O4 NPs), which are an important source of the trace element Co, essential for plants. The aim of this study was to investigate the physicochemical properties of Co3O4 NPs obtained using surfactants (cocamidopropyl betaine and alkyl dimethyl benzyl ammonium chloride) and evaluate their effect on the growth and development of pea seeds. Quantum chemical modeling showed that the interaction of Co3O4 with surfactants is energetically favorable (∆E > 2950 kcal/mol) and chemically stable (η = 0.035 eV). FTIR spectroscopy, X-ray diffraction analysis, and scanning electron microscopy revealed the formation of a stable system with a cubic crystal structure (space group Fd-3 m) and a particle size of 50–150 nm, as confirmed by dynamic light scattering. The Co3O4 NPs were predominantly spherical and oval in shape, which is important for their biological applications. Biological testing of Co3O4 NPs on pea seeds showed a significant effect on seed germination and seedling growth. The optimal concentrations of Co3O4 NPs obtained using cocamidopropyl betaine as a template were ≤ 0.01 mg/L, while those obtained with alkyl dimethyl benzyl ammonium chloride were ≤ 1.0 mg/L. At these concentrations, increased root and sprout growth was observed. The observed effects suggest that the Co3O4 NPs may influence early seed development through surface-mediated interactions and gradual availability of Co. However, the present study did not directly assess release kinetics or Co3O4 NPs localization in plant tissues; therefore, the proposed mechanism should be considered hypothetical and requires further validation.